Optimal Design On Adaptive Tuned Vibration Absorber Based On Magnetorheological Elastomer

It is well known that vibration is one of the most usual phenomenon in daily life. Vibration control, including passive vibration control and active vibration control, is designed to suppress nuisance vibration. In recent years, active vibration control techniques have been widely applied to many fields, such as aerospace industry, ships, automobiles and so on. Theories of vibration and active vibration control have also been developed. Magnetorheological elastomer (MRE) is a kind of smart materials. Its unique character is that its modulus could be controlled by the magnetic field reversely, quickly. This character makes it qualify as spring element with controllable stiffness in adaptive tuned vibration absorber and shows great promising applications.In this paper, the development trace of dynamic absorber was introduced firstly, and adaptive tuned vibration absorber (ATVA) based on MRE is discussed in detail. Then, time domain analysis, frequency domain analysis and energy analysis were used to analyse the working principle of ATVA. Based on the dynamic mechanical property of MRE, two new kind adaptive tuned vibration absorbers were proposed. A pendulum-like ATVA based on MRE was first developed. The developed system has two axisymmetric pendulum arms swaying around the same pendulum axis. The MRE smart spring element is placed between pendulum arms and pendulum axis to connect these parts together. Its frequency-shift property and vibration absorption capacity were theoretically analyzed and experimentally evaluated by employing a beam with two ends supported. Both experimental and theoretical results demonstrate that the developed MRE based pendulum-like ATVA holds wide frequency-shift range and good vibration absorption capabilities. Comparing with the previous MRE based ATVA systems, the developed pendulum-like MRE ATVA decreases the dynamic strain of MRE and its viscous damping, ensures the shift-frequency range and enhances the vibration absorption capacity. A novel dynamic stiffness tuning vibration absorber working with MR elastomers is then developed. In this design, the MRE worked in a shear mode, but its MR effect was significantly enhanced by dynamically squeezing the sample thickness with an embedded piezoelectric (PZT) actuator. With this design, both the quasi-static magnetic field and the PZT driven dynamic squeeze strain in the direction of particles chain were properly adjusted to control the vibration of the primary system. The vibration suppression capabilities were theoretically analyzed by the harmonic analysis. A combined control strategy (the tuning strategy and the ON-OFF strategy) and the control system were developed to suppress the vibration of the primary system. The simulation results indicate that the proposed MRE-PZT based DSTDVA exhibits more effective suppression capabilities than those conventional MRE based quasi-static tuned vibration absorbers; the stronger the enhancing effect of squeeze strain on MRE's shear storage modulus is, the more effective vibration suppression capabilities the proposed MRE-PZT based DSTDVA has.